I personally would like to use OneDrive since I have - like many - an Office365 subscription and have 1TB of included OneDrive space sitting there, idle, which could be better used for backup (even though, recently, I backup my Mac via Arq to OneDrive)

Personnaly, even if there are encrypted, I would never use GDrive / OneDrive to makes Backup. I'll prefere use my FTP backup provide by my server provider, or technology like https://www.online.net/en/c14

OneDrive aside, I would love to have encrypted, incremental backups. A big reason for self-hosting is to have my data away from big companies. It feels odd to then just hand those same companies an unencrypted copy of my server. I'm using the TAR method right now solely because of encryption, but it's forcing me to keep my data storage (especially in Nextcloud) to a minimum because it's not incremental.

OneDrive aside, I would love to have encrypted, incremental backups. A big reason for self-hosting is to have my data away from big companies. It feels odd to then just hand those same companies an unencrypted copy of my server. I'm using the TAR method right now solely because of encryption, but it's forcing me to keep my data storage (especially in Nextcloud) to a minimum because it's not incremental.

Actually, tar doesn't even work with large amounts of data. I have ~ 60 GB in my Nextcloud and backups with tar always crashed...